Cooling system for air-cooled engine

Abstract

A method of operating a fan for an air-cooled internal combustion engine includes starting the air-cooled internal combustion engine, operating the fan in a first operating mode in which the fan rotates in a first direction, and operating the fan in a second operating mode in which the fan rotates in a second direction.

What is claimed is: 
     
       1. A method of operating a fan for an air-cooled internal combustion engine including a blower assembly having a blower housing and a fan configured to move air through the blower housing, the method comprising:
 starting the air-cooled internal combustion engine; 
 operating the fan in a first operating mode in which the fan rotates in a first direction; 
 operating the fan in a second operating mode in which the fan rotates in a second direction; 
 stopping the air-cooled internal combustion engine; and 
 operating the fan in at least one of the first operating mode or the second operating mode after stopping the air-cooled internal combustion engine. 
 
     
     
       2. The method of  claim 1 , further comprising:
 switching between the first operating mode and the second operating mode in response to a change in an input condition. 
 
     
     
       3. The method of  claim 2 , further comprising:
 providing the input condition with a sensor. 
 
     
     
       4. The method of  claim 3 , further comprising:
 providing the input condition with a temperature sensor. 
 
     
     
       5. The method of  claim 3 , further comprising:
 providing the input condition with an air flow sensor. 
 
     
     
       6. The method of  claim 2 , further comprising:
 providing the input condition with a timer. 
 
     
     
       7. The method of  claim 2 , further comprising:
 providing the input condition with a combination of a sensor and a timer. 
 
     
     
       8. The method of  claim 2 , further comprising:
 providing the input condition with a user-input device. 
 
     
     
       9. A method of operating a fan for an air-cooled internal combustion engine including a blower assembly having a blower housing and a fan configured to move air through the blower housing, the method comprising:
 starting the air-cooled internal combustion engine; 
 determining if the fan operates in a first operating mode in which the fan rotates in a first direction or a second operating mode in which the fan rotates in a second direction; 
 upon operating the fan in one of the first operating mode or the second operating mode, monitoring an input condition while the air-cooled internal combustion engine is running; 
 detecting a change in the input condition and switching the fan from the one of the first operating mode or the second operating mode to another of the first operating mode or the second operating mode; 
 determining if the air-cooled internal combustion engine is turned off; and 
 upon determining that the air-cooled internal combustion engine is turned off, operating the fan in a shutdown mode. 
 
     
     
       10. The method of  claim 9 , wherein monitoring the input condition comprises:
 measuring a temperature, via a temperature sensor, of a portion of the air-cooled internal combustion engine. 
 
     
     
       11. The method of  claim 10 , wherein detecting the change in the input condition comprises:
 detecting an increase in the temperature above a predetermined threshold. 
 
     
     
       12. The method of  claim 9 , wherein monitoring the input condition comprises:
 measuring an air flow rate, via an air flow sensor, downstream of the fan or through a screen coupled to the blower housing. 
 
     
     
       13. The method of  claim 12 , wherein detecting the change in the input condition comprises:
 detecting a decrease in the air flow rate below a predetermined threshold. 
 
     
     
       14. The method of  claim 9 , wherein monitoring the input condition comprises:
 monitoring a timer. 
 
     
     
       15. The method of  claim 14 , wherein detecting the change in the input condition comprises:
 detecting that the timer expired. 
 
     
     
       16. The method of  claim 14 , further comprising:
 starting the timer when the air-cooled internal combustion engine starts. 
 
     
     
       17. A method of operating a fan for an air-cooled internal combustion engine including a blower assembly having a blower housing, a first fan configured to move air through the blower housing, and a second fan configured to move air through the blower housing, the method comprising:
 starting the air-cooled internal combustion engine; 
 after starting the air-cooled internal combustion engine:
 operating the first fan in a cooling mode where the first fan rotates in a first direction; and 
 operating the second fan in a debris-removal mode where the second fan rotates in a second direction opposite to the first direction. 
 
 
     
     
       18. The method of  claim 17 , further comprising:
 switching the first fan from the cooling mode to the debris-removal mode in response to:
 a temperature of a portion of the air-cooled internal combustion engine reaching a predetermined temperature threshold; 
 an air flow downstream of the first fan or through a screen coupled to the blower housing decreasing to a predetermined airflow threshold; or 
 a cooling mode timer expiring. 
 
 
     
     
       19. The method of  claim 17 , further comprising:
 switching the second fan from the debris-removal mode to the cooling mode in response to:
 a temperature of a portion of the air-cooled internal combustion engine decreasing below a predetermined temperature threshold; 
 an air flow downstream of the first fan or through a screen coupled to the blower housing increasing above a predetermined airflow threshold; or 
 a debris-removal mode timer expiring.